Predictable questions from Database Management Systems

Hi,

This post is on some of the topics from which questions are picked out mostly in NET exams.

1. Questions from Normalization:

•         A match on normal forms and their features.
•         A true / false with some features of normalization.
•         In depth questions from a particular normal form.

2. Questions from Dependencies

•         Dependencies on Relations
•         Dependencies in the result from joining relations
•         Example situations will be given and will be asked to predict the output 
•         Questions involving dependencies on decompositions are found often

3. Questions from selection, projection, joins and decompositions

•         Equations involving this can be asked
•         Problems involving this can be given and asked to predict the correct output

4. Questions from queries

•         Will be asked to frame and choose the appropriate query matching the given conditions
•         An output will be given and will be asked to select the appropriate query

5. Questions on levels of abstractions

6. Questions on constraints and keys

7.  Questions of terms used in DBMS 

•         Definitions can be provided and asked to choose the term
•         Terms may be given and asked to choose a relevant statement

Quick notes: 
(Courtesy to http://ugcnetsolved-computerscience.blogspot.in/2012/03/dbms.html)

• A table is in 1NF if there and no duplicate rows in the table. Each cell is single-valued.
• A table is in 2NF if it is in 1NF and if all non-key attributes are dependent on all of the key. A table is in 2NF if it is in 1NF and if it has no partial dependencies. 
• A table is in 3NF if it is in 2NF and if it has no transitive dependencies. 
• A table is in BCNF if it is in 3NF and if every determinant is a candiate key. 
• A table is in 4NF if it is in BCNF and it it has no multi-valued dependencies. 
• A table is in 5NF if it is in 4NF and it has no join dependency. 
• A superkey is any set of attributes such that the values of the attributes(taken together)uniquely identify one entity in the entity set.
• A candidate key is a minimal superkey.
• A primary key is one of the candidate keys, designated by the Database designer.

Next post, let me try posting some predictable and repeated kinds of questions based on june and december 2012 questions papers.